The yarn delivery or yarn supply apparatus of the above mentioned type is described in U.S. Pat. No. 4,114,823 of the assignee of the present application. This yarn delivery apparatus is capable of handling highly twisted yarn or yarn with S- or Z-twists at low tension in the region between the storage drum and the utilization position without interference with pull-off due to formation of loops, kinks or uncontrolled twists.
The yarn is supported by the guide edge of the intermediate storage element on its path in advance of the yarn sensor. This permits operation of the textile machine with very low yarn tension. Upon trouble in the machine which, for example, results in loss of tension of the yarn and in the formation of loops or twists occuring with highly twisted yarns, the loops or twists are prevented from reaching the utilization position since the narrow guide slot, in which the yarn will be guided if tension is lost, or substantially decreased, prevents the further travel of kinks or loops or twists of the yarn upon itself, and permits automatic pull-off of the yarn in a single straight thread.
In one embodiment of this yarn delivery apparatus the intermediate guide element is formed with a loop or kink deflecting extension in the form of a generally U-shaped portion projecting below the portion of the element in which the elongated narrow guide slot is formed. The deflecting element prevents catching of the yarn on the intermediate guide element when using yarns that have a strong tendency of kinking. Any kinks or loops occuring when the yarn tension will decrease will be held off laterally of the intermediate guide element by the deflecting element.
This yarn delivery apparatus enjoys a considerable commercial success. Under certain operational conditions it would be desirable to further improve the guiding of the yarn pulled off the storage drum.